Electric precipitating apparatus



May 16, 1950 J. u. F. ANiDERSEN ELECTRIC PRECIPITATING APPARATUS Filed July 51, 1947 ATTORNEY? Patented May 16, 1950 ELECTRIC PRECIPITATING APPARATUS Joakim Ulrik Frederik Andersen, Copenhagen, Denmark, assignor .to F. L. Smidth & 00., New York, N. Y., a corporation of New Jersey Application July 31, 1947, Serial No. 765,134 In Denmark August 29, 1944 Section 1, Public Law 690, August 8, 1946 Patent expires August 29, 1964 3 Claims.

This invention relates to electric precipitating apparatus of the type which includes ionizing electrodes in the form of wires and collecting electrodes of sheet or tubular form. More particularly, the invention is concerned with a precipitator of the kind referred to, in which novel means are provided for vibrating the ionizing electrodes to prevent accumulation of dust thereon, which impairs the efiiciency of the apparatus and may cause flashover.

Electric precipitators containing ionizing wires are now commonly provided with means for vibrating the wires to free them from dust accumulations. In order to be efiective, the vigratory action must be powerful and the vibrating means heretofore used have frequently caused breakage of the wires, necessitating a shut down of the apparatus for repairs.

The present invention is directed tothe provision of an electric precipitator containing ionizing wires and means for vibrating them, which permits the wires to be vibrated to the extent necessary to remove dust accumulations thereon without subjecting the wires to shocks, which are likely to cause breakage thereof. In the precipitator of the invention, the ionizing wires are suspended from a resiliently mounted support, which may be vibrated by blows applied thereto. The wires are kept taut by weighting means attached to their lower ends and are connected to the weighting means by individual springs, which partially absorb shocks to which the wires would otherwise be exposed. Preferably, the springs are attached to the weighting means by adjustable connections, so that all of the wires may be subjected to uniform tension and thus be uniformly vibrated.

For a better understanding of the invention, reference may be made to the accompanying drawing, in which Fig. 1 is a vertical sectional view through one form of precipitator constructed in accordance with the invention; and

Fig. 2 is a sectional view on the line 2--2 of Fig. 1.

The precipitator in the form illustrated includes a metallic casing Ill, which is normally grounded, as indicated at II, and has an inlet for gases to be treated and an outlet for treated gases, the inlet and outlet not being shown. At its lower end, the casing is provided with a hopper 12 for collection and discharge of precipitated material. A plurality of vertical collecting electrodes l3 of sheet form are mounted within the casing face to face and spaced apart in any suitable manner. Between adjacent collecting electrodes, there is a row of ionizing wires H, which are attached at their upper end to a frame I5. The frame is attached centrally to a beam I6, upon which rests a plate 11. The plate and beam are secured together by bolts l8 extending through the beam plate and. a spring l9 encircles each bolt and bears at its lower end against the top of plate I! and at its upper end :gafinst a washer 2c beneath the head of the A partition 2| extends across the casing near its upper end and supports a plurality of insulators 22 connected by a metal bridge 23, which is connected by a line 24 to the negative terminal of a high tension direct current source, the positive terminal of the source being grounded. A metal tube 25 passes through an opening in the bridge and is secured at its lower end to the top of plate IT. A rod 26 secured at its lower end to beam It extends through an opening in plate I! and upwardly through tube 25 to project beyond the upper end of the tube. A weight 2! mounted on the end of an arm 28 pivotally attached to a standard 29 rising from the bridge overlies the end of rod 26 and normally rests thereon. The weight is provided with an arm 30 engageable by an arm 3| on a rotating shaft 32. As the shaft rotates, arm 3| engages arm 30 and raises the weight 21, until arm 3| passes by arm 30. The weight is then released and falls by gravity upon the upper end of rod 26. The weight imparts a sharp blow to the rod and this blow is transmitted to beam [6 and frame l5. The blow causes downward movement of the beam and frame against the resistance of springs l9 and the springs restore the beam into contact with the lower face of plate I! after each blow.

A spring 33 is connected to the lower end of each wire l4 and the lower ends of the springs are connected to hooks 34 passing through a frame 35, which is generally similar in construction to frame 15 and acts as a weighting member. The shank of each hook is threaded and it passes through frame 35 and is held in place relative to frame 35 by upper and lower nuts 36, which may be adjusted so that all of the wires are subjected to uniform tension.

In the operation of the apparatus, the action of the hammer on rod 26 and the restoring action of springs l9 cause the ionizing wires to be subjected to vertical vibration, which is effective to remove accumulated dust therefrom. Although the wires are kept taut by the weigh- 3. ing frame 35, the springs 33 between the ends of the wires and the frame absorb severe shocks applied to the wires and prevent breakage thereof. The shaft 32 may be driven by any suitable means and at a rate which causes the hammer to vibrate the wires at the desired frequency. Ordinarily, it is not necessary that the wires be continuously vibrated during the operation of the apparatus and they may be vibrated for short periods separated by relatively much longer intervals.

I claim:

1. In an electric precipitator, the combination of a mounting, a support carried by the mounting and movable vertically relative thereto, means for guiding the vertical movement of the support, resilient means acting on the support and holding it in a normal position relative to the mounting, a plurality of ionizing wires depending from the support, a spring attached to the lower end of each wire, a weighting member attached to the lower ends of the springs and acting through the springs to maintain the wires taut, the member being freely movable up and down, and means for intermittently imparting vertical movement in one direction to the assembly made up of the support, wires, springs, and member against the resistance of the resilient means, the assembly being restored to normal position by said resilient means and the weighting member oscillating vertically in both directions from its normal position until it comes to rest.

2. In an electric precipitator, the combination of a mounting, a support movable vertically rel ative to the mounting, means for guiding the vertical movement of the support, resilient means by which the support is carried by the mounting and held in its normal position relative to the mount ing, a plurality of ionizing wires depending from the support, a spring attached to the lower end of each wire, a weighting member attached to the lower ends of the springs and acting through the springs to maintain the wires taut, the memher being freely movable up and down, and means for intermittently imparting vertically downward movement to the assembly made up of the support, wires, springs, and member against the resistance of the resilient means, the assembly being restored to normal position by said resilient means and the weighting member oscillating vertically in both directions from its normal position until it comes to rest.

3. In an electric precipitator, the combination of a mounting, a support movable vertically relative to the mounting, means for guiding the vertical movement of the support, resilient means by which the support is carried by the mounting and held in its normal position relative to the mounting, a plurality of ionizing wires depending from the support, a spring connected to the lower end of each wire, a weighting member below said wires and springs, the weighting member bein freely movable up and down, means for connecting each spring to the weighting member to support said member and to keep the wires taut, said connecting means being adjustable to permit varying the portion of the weight of the weighting member supported by each wire, and means for intermittently imparting vertically downward movement to the assembly made up of the support, wires, springs, connecting means, and member against the resistance of the resilient means, the assembly being restored to normal position by said resilient means and the Weighting member oscillating vertically in both directions from its normal position until it comes to rest.

J OAKIM ULRIK FREDERIK ANDERSEN.

REFERENCES CITED The following references are of record in the file of this patent:

FOREIGN PATENTS Number Country Date 230,841 Great Britain July 2, 1925 553,753 Great Britain June 3, 1943 

